Reverse reference doesn't work for Group relationship

I provided a solution in the MR that allows to select "Reverse reference: Group relationship using Content" field for the index.
Based on this value the views can filter Content per group.

Wow, would be great if that’s all it takes. Thanks a lot!

However, as I’m not using the Group module myself we’ll need either confirmation from others that this works as expected or some test coverage (which would add the Group module as a test dependency).
Could you maybe post to these other issues (or to Slack, etc.) to tell people about your solution? Maybe someone will be interested and test your MR.

PS: It seems you (like many others – it's really easy to misinterpret) are confused by the "Issue tags" field. As the guidelines → state, they aren't meant for free text tags related to the issue, but only for specific categorization purposes, usually by module maintainers.
So, if you aren't sure your current usage is correct, please just leave the field empty.